Preparation method and application of covalent organic framework material capable of adsorbing sulfonamide antibiotics

Abstract

The invention relates to a preparation method and application of a covalent organic framework material capable of adsorbing sulfonamide antibiotics. The method comprises the following steps: S1, respectively putting an amino-containing monomer and an aldehyde-containing monomer into a glass tube to obtain a mixture, then adding a solvent, performing ultrasonic uniform mixing, then adding an acetic acid solution for catalytic reaction, and performing uniform mixing to obtain a mixed solution; s2, freezing the mixed solution with liquid nitrogen, then circularly vacuumizing, sealing a glass tube, drying after treatment, cooling to room temperature, and filtering and washing to obtain a precipitate; and S3, carrying out Soxhlet extraction, repeatedly washing, and putting into a vacuum oven to obtain a product, namely the covalent organic framework material capable of adsorbing the sulfonamide antibiotics. According to the application, the adsorbent is applied to adsorption of sulfonamide antibiotics in water. The novel covalent organic framework material prepared by the invention is used for removing low-concentration sulfonamide antibiotics for the first time, and is considered as an excellent adsorption material capable of reducing the risk of water quality and guaranteeing the health of water quality.

Description

Technical Field

[0001] The invention relates to the technical field of antibiotic adsorption, and in particular to a preparation method and application of a covalent organic framework material capable of adsorbing sulfonamide antibiotics. Background Art

[0002] Antibiotics refer to a class of secondary metabolites with anti-pathogen or other activities produced by microorganisms or higher animals and plants in the process of life. They are chemical substances that can interfere with the developmental functions of other living cells at low concentrations. Since its advent, it has been widely used in various industries and has played a huge role in solving animal, plant, and human diseases. Especially in the fields of medicine and animal feed, it has excellent therapeutic effects and the ability to promote biological growth. However, with the continuous development of science and technology, the demand and use of antibiotics have continued to increase worldwide. From 2000 to 2018 alone, global antibiotic consumption increased by 46% in 20 years, and the crisis of abuse of antibiotics has also emerged. However, the absorption and digestion capacity of humans and animals for antibiotics is poor. More than 60% of antibiotics are excreted into the environment through feces or urine when they enter the human body or animal body. In addition, antibiotics used in hospitals, farms, ranches and other places will flow into the water environment with rainwater discharge. Antibiotics entering the environmental medium are difficult to be biodegraded due to their complex structure and strong inhibitory and bactericidal ability. These antibiotics have induced the production of drug-resistant strains to a great extent, posing a serious threat to the ecological environment and public health safety.

[0003] At present, my country's antibiotic emissions rank first in the world. The "Action Plan for the Control of New Pollutants" released in 2022 points out that it is necessary to strengthen the monitoring and control of antibiotics in environmental media, which have the characteristics of a wide variety, complex structure, diverse forms, and unknown environmental effects. By analyzing the distribution of antibiotics in areas with higher ecological risk levels, it can be seen that sulfonamide antibiotics account for the majority of the proportion due to their difficulty in degradation. They are the main component of residual antibiotics in the water environment, with a concentration of up to μg / L. The widespread spread of the resistance genes produced makes it have extremely high ecological and environmental risks. The effective reduction of low-concentration sulfonamide antibiotics is one of the key points and difficulties in water quality risk control.

[0004] In 2005, Professor Yaghi, the originator of MOFs, officially announced the advent of covalent organic frameworks (COFs) in a Science article. Covalent organic frameworks are a new class of crystalline porous materials connected by covalent bonds. They have highly ordered pore sizes, excellent structural regularity, high specific surface area, inherent porosity, and adjustable chemical stability. They have broad application prospects in the fields of gas adsorption and storage, water adsorption and desorption, photoelectric conversion, heterogeneous catalysis, and energy storage and conversion. At present, the research on the structural development of covalent organic frameworks is mainly focused on two-dimensional covalent organic frameworks obtained from two-dimensional sheets; the development of new structures of three-dimensional covalent organic frameworks is greatly restricted due to the lack of spatially symmetrical organic building units and low reversible reactions during synthesis. So far, only covalent organic framework materials of topological types such as dia, ctn, bor, ffc, rra, srs, and pts have been reported in the huge three-dimensional topological database. Covalent organic frameworks have several outstanding features: (1) Strong designability: Different functional groups can be grafted by selecting different reaction conditions, and the pores are regular, comparable to the highly porous materials in nature such as "honeycombs", resulting in diverse building blocks and functions; (2) Lightweight and stable properties: Covalent organic framework materials are mainly composed of lightweight elements such as carbon, hydrogen, oxygen, and nitrogen, with extremely low density. At the same time, covalent bonds make them not easily destroyed even in high temperature or acidic environments; (3) Highly ordered porous structure.

[0005] (1) The existing traditional wastewater treatment process based on biochemical technology cannot effectively remove antibiotics, resulting in a large amount of antibiotic parent and biological metabolites discharged into the natural water environment, seriously threatening the safety of the water environment. Physicochemical treatment technology, such as the typical advanced oxidation process, is very expensive and may produce toxic and harmful byproducts.

[0006] (2) Although the existing adsorption technology is the most economical and effective technology for removing antibiotics from water, it is prone to secondary pollution. In order to reflect the advantages of the material, the initial concentration is usually selected at the mg / L level. For example, the initial concentration is set to 10 mg / L. Although it can achieve a certain removal rate, it loses its practical application significance. Summary of the invention

[0007] In order to solve the above problems, the present invention provides a preparation method and application of a covalent organic framework material capable of adsorbing sulfonamide antibiotics.

[0008] The technical solution of the present invention is: a method for preparing a covalent organic framework material capable of adsorbing sulfonamide antibiotics, wherein the surface of the covalent organic framework material has a mesoporous structure with a pore diameter of 2 to 3 nm and contains sulfonic acid groups; the preparation method comprises the following steps:

[0009] S1. 32-33 mg of an amino group-containing monomer and 84-87 mg of an aldehyde group-containing monomer are placed in glass tubes to obtain a mixture, and then 2.5-3.5 mL of a solvent is added, and the mixture is uniformly mixed by ultrasonication for 18-20 min, and then a 3-9 mol / L acetic acid solution is added thereto for catalytic reaction, and the mixture is uniformly stirred to obtain a mixed solution;

[0010] S2, freeze the mixed solution with liquid nitrogen, then circulate and vacuumize for 3 to 5 times, seal the glass tube, and react at 110 to 130° C. for 60 to 84 hours after the treatment; after the reaction, cool to room temperature, filter and wash the precipitate, and transfer it from the glass tube to a centrifuge tube;

[0011] S3, extract the precipitate obtained in S2 with tetrahydrofuran, acetone, dimethyl sulfoxide and ethanol solution in sequence for 5 to 7 hours, repeat washing 3 to 4 times to remove unreacted monomers, and when the washing agent is colorless, wrap the precipitate with paper into a tea bag shape and place it in a vacuum oven at 110 to 130°C for 10 to 14 hours to obtain a dark red crystal, which is a covalent organic framework material capable of adsorbing sulfonamide antibiotics;

[0012] Description: Acetic acid is used as a catalyst when synthesizing a covalent organic framework, so that the synthesized material has a rigid C=N bond, and the final structure has better crystallinity and more regular pores; compared with other adsorbents, the series of covalent organic framework adsorbents provided by the present invention have a higher adsorption capacity, good selectivity, and stable structure. At the same time, the present invention can also expand the application scope of this covalent organic framework. For new pollutants containing "-NH2", the design principles of the present invention can be followed to introduce sulfonic acid groups and design a series of covalent organic framework adsorbents to select the most suitable materials for the target pollutants.

[0013] Further, in step S1, the amino-containing monomer is one of p-phenylenediamine, 2,5-diaminobenzenesulfonic acid, paraphenyleneamine-2,5-disulfonic acid, benzidine, and 4,4'-diamino-3,3'-biphenyldisulfonic acid; the aldehyde-containing monomer is trialdehyde phloroglucinol; and the covalent organic framework material is one of TpPa, TpPa-SO3H, TpPa-(SO3H)2, TpBD, and TpBD-(SO3H)2;

[0014] Note: The above covalent organic framework materials all have the characteristics of high adsorption capacity, good selectivity and stable structure.

[0015] Furthermore, the solvent is obtained by mixing 1,4-dioxane and mesitylene in a volume ratio of 1 to 4:1;

[0016] Description: 1,4-Dioxane and mesitylene are both non-polar solvents that can dissolve many organic precursors well and provide suitable reaction media to promote the formation of specific types of chemical bonds, thereby ensuring yield and efficiency.

[0017] Furthermore, the 1,4-dioxane contains a stabilizer BHT, with a purity of ≥99%; the mesitylene has a purity of ≥97%; the acetic acid is ppb grade, with a purity of ≥99.7%;

[0018] Note: The purity limit of each component can ensure the purity of the covalent organic framework material, thereby improving its adsorption effect on sulfonamide antibiotics.

[0019] Furthermore, the cyclic vacuuming method is a freeze-pump-thaw cyclic degassing treatment;

[0020] Note: This step can effectively create an oxygen-free environment and prevent oxygen from interfering during the material synthesis process.

[0021] Further, in step S3, the drying temperature of the Soxhlet extraction is 60-100°C;

[0022] Note: When the drying temperature of the Soxhlet extraction is set within the above range during the water bath method, the monomers in the material can be processed cleanly, and the designed material does not contain impurities, thereby increasing the contact area between the sulfonamide drugs and the material; thereby, the sulfonamide drug molecules can better enter the pores of the material and be adsorbed, further improving the removal efficiency of sulfonamide antibiotics.

[0023] Further, after step S1, the mixed solution is subjected to functionalization treatment, and the method of the functionalization treatment is: Au nanoparticles and non-ionic surfactant TritonX-100 are stirred and mixed at a mass ratio of 3 to 4:5 to obtain a mixture; then the mixed material and the mixed solution are mixed at a volume ratio of 1:3 to 5 to obtain a mixture, and the mixture is placed in an irradiation reactor, and microwave pulse irradiation and gamma-ray assisted irradiation treatment are performed in sequence; wherein the parameters of the microwave pulse irradiation are: microwave power of 60 to 100 W, pulse width of 30 to 500 ns, pulse repetition frequency of 10 to 800 Hz, and treatment time of 20 to 50 min; during the gamma-ray assisted irradiation process, the absorbed dose rate of the mixture is 10 to 30 Gy / min, and the absorbed dose is 400 to 1600 Gy;

[0024] Description: When Au nanoparticles and TritonX-100 are mixed in a specific mass ratio, the nonionic surfactant Triton-100 can effectively wrap the Au nanoparticles to prevent them from agglomerating in large quantities. After being subsequently mixed with the mixed solution in a volume ratio, this good dispersibility is maintained; during the irradiation process, the uniformly dispersed system is conducive to the uniform transfer of irradiation energy, thereby making the microstructure of the organic framework material more regular. The regular structure can provide more specific adsorption sites and improve the affinity for sulfonamide antibiotics.

[0025] Au nanoparticles interact with sulfonic acid under microwave and gamma ray irradiation, thus changing the electron cloud distribution of sulfonic acid, making it easier to accept or give electrons, thereby improving its catalytic activity. TritonX-100 can change the interface properties of the reaction system during irradiation, so that it promotes better dispersion of sulfonic acid in the reaction system, and cooperates with Au nanoparticles to form a microenvironment around sulfonic acid that is conducive to catalytic reaction, which is conducive to the contact between substrate molecules and sulfonic acid active centers. Microwave irradiation can quickly transfer energy to various components in the reaction system, and gamma ray irradiation provides higher energy excitation; under this dual irradiation mode, energy can be effectively transferred to sulfonic acid molecules, changing the vibration and rotation state of the molecules, making them in a high-energy state that is more conducive to catalytic reaction; from a microscopic perspective, the electromagnetic field of the microwave pulse interacts with the molecules in the material, causing the electron cloud distribution around the sulfonic acid group to change; this change prompts the sulfonic acid group to adjust its orientation to achieve a relatively low-energy ordered arrangement state, enhancing its interaction with sulfonamide antibiotics. When catalyzing electrophilic substitution reactions, this adsorbent may promote the reaction by providing an acidic environment (the acidity of the sulfonic acid group); the presence of Au nanoparticles and TritonX-100 can regulate the efficiency and direction of energy transfer. By functionalizing the covalent organic framework material with sulfonic acid, an acid catalyst with high acid catalytic activity and good selectivity can be obtained, allowing the sulfonic acid to better exert its catalytic effect.

[0026] Furthermore, the microwave pulse irradiation and the gamma-ray assisted irradiation treatment adopt an alternating irradiation method: during the microwave pulse irradiation treatment, after each preheating for 3 to 10 minutes, the microwave pulse irradiation treatment is stopped for 2 to 5 minutes, and the gamma-ray assisted irradiation treatment is performed when the microwave pulse irradiation treatment is stopped. When the microwave pulse irradiation treatment is completed, the absorbed dose rate of the mixture is increased by 50 to 80 Gy / min until the absorbed dose of the gamma-ray assisted irradiation treatment is met;

[0027] Description: Under the combined action of microwave pulse irradiation and γ-ray assisted irradiation, more active sites will be generated on the surface of the organic framework material. These active sites may be formed by the breaking and recombination of chemical bonds. For sulfonamide antibiotics, these active sites can serve as the center of chemical reaction with antibiotic molecules, and sulfonamide antibiotics can be fixed on the organic framework material through chemical bonding or electrostatic action. In addition, the preheating and suspension during microwave pulse irradiation, as well as the alternation with γ-ray assisted irradiation, can accurately control the microstructure of the covalent organic framework material. For example, more pore structures will be formed inside the material to better adapt to sulfonamide antibiotics of different sizes, thereby improving the removal efficiency of sulfonamide antibiotics.

[0028] An application of a covalent organic framework material capable of adsorbing sulfonamide antibiotics, wherein the covalent organic framework material prepared by the above-mentioned method for preparing a covalent organic framework material capable of adsorbing sulfonamide antibiotics is applied in adsorbing sulfonamide antibiotics in water;

[0029] The application method is as follows: adding the covalent organic framework material to a polluted water body containing sulfonamide antibiotics, and adsorbing the covalent organic framework material at 28-32° C. and 175-185 rpm for 1.5-2.5 hours, wherein the mass ratio between the amount of the covalent organic framework material added and the content of the sulfonamide antibiotics in the water body is 10 mg:1 μg;

[0030] Note: From the experimental results, it can be seen that the covalent organic framework material prepared in this application has the characteristics of high specific surface area, high porosity, high stability, etc., and has a better removal effect on trace pollutants.

[0031] Furthermore, after the vibration adsorption, the covalent organic framework material adsorbed with sulfonamide antibiotics is immersed in 0.1 mol / L hydrochloric acid, and ultrasonically shaken and washed 3 to 7 times at room temperature, each treatment for 1.8 to 2.2 hours, so that the sulfonamide antibiotics are desorbed, thereby realizing the recycling of the covalent organic framework material;

[0032] Note: The covalent organic framework material can be regenerated by treating it with hydrochloric acid at the above concentration, thereby achieving recycling.

[0033] Compared with the existing covalent organic framework adsorbent, the beneficial effects of the present invention are:

[0034] (1) Driven by the goal of "reducing pollution and reducing carbon emissions" in the water treatment industry, the present invention uses the principles of framework chemistry, simulates and estimates the molecular size of sulfonamide antibiotics, and through reasonable design, successfully prepares a new type of covalent organic framework material that can effectively remove trace antibiotics in wastewater. At the same time, considering that specific reaction groups are the key to achieving selective adsorption of low-concentration sulfonamide antibiotics, sulfonated materials are the key to treating amino groups, and electrophilic substitution reactions between sulfonic acid groups and amino groups are easier to achieve. Therefore, a covalent organic framework material with selective adsorption groups is proposed to achieve deep purification of sulfonamide antibiotics and ensure the health and safety of water quality. The new covalent organic framework material prepared by the present invention is used for the first time to remove low-concentration sulfonamide antibiotics and is considered to be an excellent adsorption material that can reduce water quality risks and ensure the health of water quality.

[0035] (2) The present invention effectively utilizes TritonX-100 to wrap Au nanoparticles through functionalization treatment of the mixed solution to avoid large-scale agglomeration of Au nanoparticles, thereby providing more specific adsorption sites and improving the affinity for sulfonamide antibiotics. The electromagnetic field of microwaves interacts with the molecules in the covalent framework organic material, causing the electron cloud distribution around the sulfonic acid group to change, prompting the sulfonic acid group to adjust its own orientation to achieve a relatively low-energy ordered arrangement state, further enhancing its catalytic activity, improving its interaction with sulfonamide antibiotics, and improving the adsorption effect of the covalent organic framework material on low-concentration sulfonamide antibiotics. BRIEF DESCRIPTION OF THE DRAWINGS

[0036] Figure 1 is the XRD pattern of TpPa-SO3H prepared under different solvent ratios of the present invention;

[0037] Figure 2 is the XRD pattern of TpPa-SO3H prepared at different catalyst concentrations of the present invention;

[0038] Figure 3 This is a comparison chart of the adsorption performance of TpPa-SO3H-1 and TpPa-SO3H-2 of the present invention on sulfonamide antibiotics;

[0039] Figure 4 It is a roadmap for preparing covalent organic framework adsorbents TpPa-SO3H, TpBD, and TpBD-(SO3H)2 under the optimal preparation conditions of the present invention;

[0040] Figure 5 The covalent organic framework adsorbents TpPa-SO3H, TpBD, and TpBD-(SO3H)2 prepared under the optimal preparation conditions of the present invention from left to right;

[0041] Figure 6is the XRD pattern of TpBD prepared under the optimal preparation conditions of the present invention;

[0042] Figure 7 This is a SEM image of the covalent organic framework adsorbent TpBD prepared under the optimal preparation conditions of the present invention;

[0043] Figure 8 This is a graph showing the adsorption performance of TpPa-SO3H, TpBD, and TpBD-(SO3H)2 prepared by the present invention for sulfonamide antibiotics. DETAILED DESCRIPTION

[0044] In order to further illustrate the methods and effects of the present invention, the technical scheme of the present invention will be described clearly and completely in combination with experiments. Experimental methods without specific conditions in the implementation plan are all carried out under conventional conditions; the reagents and materials used, unless otherwise specified, can be obtained from commercial channels.

[0045] Embodiment 1: A method for preparing a covalent organic framework material capable of adsorbing sulfonamide antibiotics, wherein the surface of the covalent organic framework material has a mesoporous structure with a pore size of 2 to 3 nm and contains sulfonic acid groups; the preparation method comprises the following steps:

[0046] S1, 32.4 mg of an amino-containing monomer and 84.6 mg of an aldehyde-containing monomer were placed in glass tubes to obtain a mixture, and then 3 mL of a solvent was added, and the mixture was uniformly mixed by ultrasonication for 19 min, and then 0.6 mL of a 6 mol / L acetic acid solution was added thereto for catalytic reaction, and the mixture was uniformly stirred to obtain a mixed solution;

[0047] S2, freeze the mixed solution with liquid nitrogen, then circulate and vacuumize for 4 times, seal the glass tube, and react at 120°C for 72 hours after the treatment; after the reaction, cool to 27°C, filter and wash the precipitate and transfer it from the glass tube to a centrifuge tube; the circulatory vacuuming method is a freeze-pump-thaw cycle degassing treatment;

[0048] S3, the precipitate obtained in S2 is subjected to Soxhlet extraction treatment with tetrahydrofuran, acetone, dimethyl sulfoxide and ethanol solution in sequence for 6 hours, the drying temperature of the Soxhlet extraction is 80°C, and the washing is repeated 3 times to remove unreacted monomers. When the washing agent is colorless, the precipitate is wrapped in paper into a tea bag shape and placed in a vacuum oven at 120°C for reaction for 12 hours. The obtained dark red crystals are the covalent organic framework material capable of adsorbing sulfonamide antibiotics;

[0049] In step S1, the monomer containing amino group is 2,5-diaminobenzenesulfonic acid, the monomer containing aldehyde group is trialdehyde phloroglucinol; the solvent is 1,4-dioxane and mesitylene mixed in a volume ratio of 4:1; the covalent organic framework material is TpPa-SO3H; 1,4-dioxane contains stabilizer BHT with a purity of 99%; mesitylene has a purity of 97%; acetic acid is ppb grade with a purity of 99.7%;

[0050] Application of a covalent organic framework material capable of adsorbing sulfonamide antibiotics, which is used in adsorbing sulfonamide antibiotics in water;

[0051] The application method is as follows: adding the covalent organic framework material to the contaminated water containing sulfonamide antibiotics, and adsorbing it under vibration at 30°C and 180rpm for 2.0h, wherein the concentration of the contaminated water containing sulfonamide antibiotics is 10μg / L; then weighing 10mg of the covalent organic framework material into 100mL of the contaminated water containing sulfonamide antibiotics, and adsorbing it under vibration at 30°C and 180rpm for 2.0h, and testing the concentration of each sulfonamide antibiotic in the adsorbed solution; then immersing the covalent organic framework material adsorbing the sulfonamide antibiotics in 0.1mol / L hydrochloric acid after the vibration adsorption, and washing it under ultrasonic vibration at 27°C for 2h to desorb the sulfonamide antibiotics, thereby realizing the recycling of the adsorbent.

[0052] Example 2: Different from Example 1, in step S1, 32 mg of amino-containing monomer and 84 mg of aldehyde-containing monomer were placed in 10 mL glass tubes respectively to obtain a mixture, and then 2.5 mL of solvent was added and mixed evenly by ultrasonication for 18 min.

[0053] Example 3: Different from Example 1, in step S1, 33 mg of amino-containing monomer and 87 mg of aldehyde-containing monomer were placed in 10 mL glass tubes respectively to obtain a mixture, and then 3.5 mL of solvent was added and mixed evenly by ultrasonication for 20 min.

[0054] Example 4: The difference from Example 1 is that in step S1, an acetic acid solution with a concentration of 3 mol / L is then added thereto to catalyze the reaction, and the mixture is stirred evenly to obtain a mixed solution.

[0055] Example 5: The difference from Example 1 is that in step S1, an acetic acid solution with a concentration of 9 mol / L is then added thereto to catalyze the reaction, and the mixture is stirred evenly to obtain a mixed solution.

[0056] Example 6: Different from Example 1, in step S2, the mixed solution is frozen with liquid nitrogen, then vacuumized three times, the glass tube is sealed, and after the treatment is completed, the reaction is carried out at 110°C for 60 hours.

[0057] Example 7: Different from Example 1, in step S2, the mixed solution is frozen with liquid nitrogen, and then vacuumed for 5 times, the glass tube is sealed, and after the treatment, the reaction is carried out at 130° C. for 84 hours;

[0058] Example 8: Different from Example 1, in step S3, tetrahydrofuran, acetone, dimethyl sulfoxide and ethanol solution are used for treatment for 5 hours respectively, the drying temperature of Soxhlet extraction is 60°C in a water bath, and the washing is repeated 3 times to remove unreacted monomers. When the washing agent is colorless, the precipitate is wrapped in paper into a tea bag shape and placed in a vacuum oven at 110°C for reaction for 10 hours. The obtained dark red crystals are the covalent organic framework material capable of adsorbing sulfonamide antibiotics.

[0059] Example 9: Different from Example 1, in step S3, tetrahydrofuran, acetone, dimethyl sulfoxide and ethanol solution are treated in a water bath at 100°C for 7 hours, and the washing is repeated 4 times to remove unreacted monomers. When the detergent is colorless, the precipitate is wrapped in paper into a tea bag shape and placed in a vacuum oven at 130°C for reaction for 14 hours. The obtained dark red crystals are the covalent organic framework material that can adsorb sulfonamide antibiotics.

[0060] Example 10: Different from Example 1, in step S1, the solvent is 1,4-dioxane and mesitylene mixed in a volume ratio of 1:1.

[0061] Example 11: Different from Example 1, in step S1, the solvent is a mixture of 1,4-dioxane and mesitylene in a volume ratio of 2:1.

[0062] Example 12: Different from Example 1, in step S1, the amino-containing monomer is p-phenylenediamine.

[0063] Example 13: Different from Example 1, in step S1, the amino-containing monomer is paraphenyleneamine-2,5-disulfonic acid.

[0064] Example 14: Different from Example 1, in step S1, the amino-containing monomer is benzidine.

[0065] Example 15: Different from Example 1, in step S1, the amino-containing monomer is 4,4'-diamino-3,3'-biphenyldisulfonic acid.

[0066] Example 16: Different from Example 1, the mixed solution is functionalized after step S1, and the method of functionalization is as follows: Au nanoparticles and non-ionic surfactant TritonX-100 are stirred and mixed at a mass ratio of 7:10 to obtain a mixture; then the mixed material and the mixed solution are mixed at a volume ratio of 1:4 to obtain a mixture, and the mixture is placed in an irradiation reactor, and subjected to microwave pulse irradiation and γ-ray assisted irradiation treatment in sequence; wherein the parameters of microwave pulse irradiation are: microwave power of 80 W, pulse width of 270 ns, pulse repetition frequency of 400 Hz, and treatment time of 35 min; during the γ-ray assisted irradiation process, the absorbed dose rate of the mixed solution is 20 Gy / min, and the absorbed dose is 1000 Gy.

[0067] Example 17: Different from Example 16, the mixed solution is subjected to functionalization treatment after step S1, and the method of functionalization treatment is: Au nanoparticles and non-ionic surfactant TritonX-100 are stirred and mixed in a mass ratio of 3:5 to obtain a mixture; then the mixed material and the mixed solution are mixed in a volume ratio of 1:3 to obtain a mixture, and the mixture is placed in an irradiation reactor, and subjected to microwave pulse irradiation and γ-ray assisted irradiation treatment in sequence.

[0068] Example 18: Different from Example 16, the mixed solution is subjected to functionalization treatment after step S1, and the method of functionalization treatment is: Au nanoparticles and non-ionic surfactant TritonX-100 are stirred and mixed in a mass ratio of 4:5 to obtain a mixture; then the mixed material and the mixed solution are mixed in a volume ratio of 1:5 to obtain a mixture, and the mixture is placed in an irradiation reactor, and subjected to microwave pulse irradiation and γ-ray assisted irradiation treatment in sequence.

[0069] Example 19: Different from Example 16, the parameters of microwave pulse irradiation are: microwave power is 60 W, pulse width is 30 ns, pulse repetition frequency is 10 Hz, and treatment time is 20 to 50 min; during the γ-ray assisted irradiation process, the absorbed dose rate of the mixed solution is 10 Gy / min, and the absorbed dose is 400 Gy.

[0070] Example 20: Different from Example 16, the parameters of microwave pulse irradiation are: microwave power is 100 W, pulse width is 500 ns, pulse repetition frequency is 800 Hz, and treatment time is 50 min; during the γ-ray assisted irradiation process, the absorbed dose rate of the mixed solution is 30 Gy / min, and the absorbed dose is 1600 Gy.

[0071] Example 21: Different from Example 16, microwave pulse irradiation and gamma-ray assisted irradiation treatment are carried out by alternating irradiation method: during the microwave pulse irradiation treatment, after each preheating for 6 minutes, it is stopped for 4 minutes, and gamma-ray assisted irradiation treatment is carried out when the microwave pulse irradiation treatment is stopped. After the microwave pulse irradiation treatment is completed, the absorbed dose rate of the mixed solution is increased by 50 to 80 Gy / min until the absorbed dose of the gamma-ray assisted irradiation treatment is met.

[0072] Example 22: Different from Example 21, during the microwave pulse irradiation treatment, after each preheating for 3 minutes, the treatment is stopped for 2 minutes, and the γ-ray assisted irradiation treatment is carried out when the microwave pulse irradiation treatment is stopped. When the microwave pulse irradiation treatment is completed, the absorbed dose rate of the mixed solution is increased by 50Gy / min until the absorbed dose of the γ-ray assisted irradiation treatment is met.

[0073] Example 23: Different from Example 21, during the microwave pulse irradiation treatment, after each 10 minutes of preheating, the treatment is stopped for 5 minutes, and the γ-ray assisted irradiation treatment is carried out when the microwave pulse irradiation treatment is stopped. When the microwave pulse irradiation treatment is completed, the absorbed dose rate of the mixed solution is increased by 80Gy / min until the absorbed dose of the γ-ray assisted irradiation treatment is met.

[0074] Experimental Example: The description of this experimental example is based on the scheme described in Example 1, and is intended to illustrate the practical application effect of the present invention.

[0075] The adsorption performance of the prepared TpPa-SO3H-1 and TpPa-SO3H-2 and the covalent organic framework adsorbent for sulfonamide antibiotics was tested. The specific steps are as follows: five typical sulfonamide antibiotics (sulfamethoxazole, sulfadiazine, sulfapyridine, sulfadimethoxine, and sulfachloropyridazine) were selected to prepare 10 μg / L simulated water, and 10 mg of each adsorbent was weighed into 100 mL of sulfonamide antibiotic simulated water, and adsorbed at 30°C and 180 rpm for 2 h. The concentration of each sulfonamide antibiotic in the adsorbed solution was tested. The test results are shown in FIG. Figures 1 to 8 As shown, the average adsorption rate of the covalent framework organic material obtained in each embodiment for the species sulfonamide antibiotics is taken as a reference, and the results are shown in Table 1.

[0076] Conclusion: Figure 1It can be seen that the amount of solvent used will affect whether the reaction monomers can be completely dissolved, and will also affect the interaction between the monomers. The appropriate amount of solvent can provide a good reaction environment for the polymerization reaction, forming a polymer network with good pores, thereby increasing the crystallinity of the material. By adding different proportions of solvents, covalent organic framework adsorbents TpPa-SO3H with different properties can be prepared. Among them, it can be observed that only when the volume ratio of 1,4-dioxane and mesitylene is 4:1, can the characteristic peaks before 5° (circled) be observed, corresponding to the 100 crystal plane. Therefore, the optimal solvent ratio is 1,4-dioxane and mesitylene (v:v=4:1).

[0077] Figure 2 The XRD diagram of TpPa-SO3H prepared with different catalyst concentrations shows that the concentration of the catalyst can have a certain effect on the crystallinity of the covalent organic framework adsorbent TpPa-SO3H. The catalyst plays an important role in the condensation reaction of aldehydes and ammonia derivatives. The reaction is generally carried out under acid catalysis, and the carbonyl oxygen and proton combine to increase the activity of the carbonyl group: the condensation reaction of aldehydes and ammonia is reversible, and the condensation product can be hydrolyzed into raw materials under the action of dilute acid. By adding catalysts of different concentrations, covalent organic framework adsorbent TpPa-SO3H with different properties can be prepared. From the XRD diagram, it can be found that the addition of 3M and 6M acetic acid both have peaks at around 4.92°, corresponding to the 100 crystal plane, and there is no monomer impurity peak. Therefore, both catalyst concentrations can generate materials with good crystallinity, but at the concentration of 6M acetic acid, the crystallization peak is more prominent.

[0078] From the XRD pattern and Figure 3 Taken together, the optimal catalytic concentration of acetic acid is 6M.

[0079] Under the optimal preparation conditions (see Figure 4 ) prepared covalent organic framework adsorbents TpPa-SO3H, TpBD, TpBD-(SO3H)2 (see Figure 5 ), and XRD test was performed on TpBD as a representative (see Figure 6 ) and SEM-EDS testing (see Figure 7 ). SEM test showed that the material had a rough porous rod-like structure, and EDS test showed that only C, H, N, and O elements existed in the material.

[0080] Figure 8 It can be seen that even when the initial concentration is only 10 μg / L, the adsorption efficiency of the synthesized material for sulfonamide antibiotics can reach more than 80%.

[0081] 1. Investigate the effect of preparation methods on the adsorption properties of covalent organic framework materials

[0082] Control group 1: Different from Example 16, no Au nanoparticles and non-ionic surfactant Triton X-100 were added.

[0083] Control group 2: Different from Example 16, the addition ratio of Au nanoparticles and non-ionic surfactant TritonX-100 is 1:1.

[0084] Control group 3: Different from Example 16, the microwave pulse irradiation was replaced by electron beam irradiation, and the irradiation intensity remained unchanged.

[0085] Table 1 Adsorption properties of covalent organic framework materials obtained in Examples 1 to 23 and Control Groups 1 to 3

[0086]

[0087] Conclusion: From the data in Table 1, it can be seen that the covalent organic framework materials obtained in Examples 1 to 15 can achieve an adsorption efficiency of more than 80% for sulfonamide antibiotics even when the initial concentration of sulfonamide antibiotics is only 10 μg / L, and the effect is better under the parameters of Example 1; and compared with Examples 1 to 15, the adsorption effect of the covalent organic framework materials in Examples 16 to 22 has been significantly further improved, and in the best case it can reach 88.3%, which indicates that the functionalization treatment of the mixed solution can be more conducive to the orderly arrangement of the sulfonic acid groups inside the covalent framework organic material, thereby enhancing its interaction with the sulfonic acid groups in the sulfonamide antibiotics, and the functionalization treatment can provide more adsorption sites, thereby further improving its adsorption effect on sulfonamide antibiotics;

[0088] By comparing Examples 16 to 18 and Control Groups 1 to 2, it can be seen that the absence of Au nanoparticles and non-ionic surfactant TritonX-100 in Control Group 1 and the addition of Au nanoparticles and non-ionic surfactant TritonX-100 in Control Group 2 at a ratio of 1:5 will both weaken the adsorption effect on sulfonamide antibiotics. This is because Au nanoparticles interact with sulfonic acid under microwave and gamma ray irradiation, thereby changing the electron cloud distribution of sulfonic acid, making it easier to accept or give electrons, thereby improving its catalytic activity. TritonX-100 can change the interfacial properties of the reaction system during irradiation, thereby promoting better dispersion of sulfonic acid in the reaction system, and synergizing with Au nanoparticles to form a favorable ionomer around the sulfonic acid. The microenvironment in which the catalytic reaction is carried out is conducive to the contact between the sulfonamide antibiotics and the sulfonic acid active center, thereby improving the adsorption effect; and the addition ratio of Au nanoparticles and the non-ionic surfactant TritonX-100 can determine the wrapping effect of the non-ionic surfactant Triton-100 on the Au nanoparticles, preventing them from agglomerating in large quantities, further affecting the action ability of the Au nanoparticles and TritonX-100, and Examples 16 to 18 can have their respective effects under the premise of preventing their agglomeration in large quantities. It can be understood that the TritonX-100 in Examples 16 to 18 does not completely wrap the surface of the Au nanoparticles, that is, there are exposure points, while the 1:5 in the control group 2 allows TritonX-100 to completely wrap the surface of the Au nanoparticles;

[0089] From the comparison of Example 16, Example 19-Example 20 and Control Group 3, it can be seen that replacing microwave pulse irradiation with electron beam irradiation will cause the covalent framework organic adsorbent to have a poor adsorption effect on sulfonamide antibiotics. This is because the electron beam may cause the atoms on the surface of the Au nanoparticles to shift or sputter, changing their original physical and chemical properties, thereby affecting the interaction with the sulfonic acid group and the sulfonamide antibiotics, and for non-ionic surfactants such as TritonX-100, electron beam irradiation may break its molecular chain, thereby weakening its function in the mixture; and from the comparison of Example 21-Example 23 and Example 16, Example 19-Example 20, it can be seen that not using alternating irradiation for microwave pulse irradiation and γ-ray assisted irradiation treatment in Example 16, Example 19-Example 20 will also cause the micro-control effect of the covalent organic framework material to be weakened, while the alternating irradiation treatment in Example 21-Example 23 can further reduce the adsorption of sulfonamide antibiotics by improving the size adaptation effect of the material pores to sulfonamide antibiotics. In summary, the present invention provides a covalent organic framework material that has a good adsorption effect on low-concentration sulfonamide antibiotics.

Claims

1. A method for preparing a covalent organic framework material capable of adsorbing sulfonamide antibiotics, characterized in that: The covalent organic framework material has a mesoporous structure on its surface, a pore size of 2 to 3 nm, and contains sulfonic acid groups; the preparation method comprises the following steps: S1. 32-33 mg of an amino group-containing monomer and 84-87 mg of an aldehyde group-containing monomer are placed in glass tubes to obtain a mixture, and then 2.5-3.5 mL of a solvent is added, and the mixture is uniformly mixed by ultrasonication for 18-20 min, and then a 3-9 mol / L acetic acid solution is added thereto for catalytic reaction, and the mixture is uniformly stirred to obtain a mixed solution; S2, freeze the mixed solution with liquid nitrogen, then circulate and vacuumize for 3 to 5 times, seal the glass tube, and react at 110 to 130° C. for 60 to 84 hours after the treatment; after the reaction, cool to room temperature, filter and wash the precipitate, and transfer it from the glass tube to a centrifuge tube; S3. The precipitate obtained in S2 is extracted with tetrahydrofuran, acetone, dimethyl sulfoxide and ethanol solution in sequence for 5 to 7 hours, and the washing is repeated 3 to 4 times to remove unreacted monomers. When the washing agent is colorless, the precipitate is wrapped in paper into a tea bag shape and placed in a vacuum oven at 110 to 130°C for reaction for 10 to 14 hours. The obtained dark red crystals are the covalent organic framework material capable of adsorbing sulfonamide antibiotics.

2. The method for preparing a covalent organic framework material capable of adsorbing sulfonamide antibiotics according to claim 1, characterized in that: In step S1, the amino-containing monomer is one of p-phenylenediamine, 2,5-diaminobenzenesulfonic acid, paraphenyleneamine-2,5-disulfonic acid, benzidine, and 4,4'-diamino-3,3'-biphenyldisulfonic acid; the aldehyde-containing monomer is trialdehyde pyroglucin; and the covalent organic framework material is one of TpPa, TpPa-SO3H, TpPa-(SO3H)2, TpBD, and TpBD-(SO3H)2.

3. The method for preparing a covalent organic framework material capable of adsorbing sulfonamide antibiotics according to claim 1, characterized in that: The solvent is obtained by mixing 1,4-dioxane and mesitylene in a volume ratio of 1 to 4:

1.

4. The method for preparing a covalent organic framework material capable of adsorbing sulfonamide antibiotics according to claim 3, characterized in that: The 1,4-dioxane contains stabilizer BHT with a purity of ≥99%; the purity of mesitylene is ≥97%; and the acetic acid is of ppb grade with a purity of ≥99.7%.

5. The method for preparing a covalent organic framework material capable of adsorbing sulfonamide antibiotics according to claim 1, characterized in that: The cyclic vacuuming method is a freeze-pump-thaw cyclic degassing process.

6. The method for preparing a covalent organic framework material capable of adsorbing sulfonamide antibiotics according to claim 1, characterized in that: In step S3, the drying temperature of the Soxhlet extraction is 60-100°C.

7. The method for preparing a covalent organic framework material capable of adsorbing sulfonamide antibiotics according to claim 1, characterized in that: After step S1, the mixed solution is subjected to functionalization treatment, and the method of the functionalization treatment is: Au nanoparticles and non-ionic surfactant TritonX-100 are stirred and mixed at a mass ratio of 3 to 4:5 to obtain a mixture; then the mixed material and the mixed solution are mixed at a volume ratio of 1:3 to 5 to obtain a mixture, and the mixture is placed in an irradiation reactor, and microwave pulse irradiation and gamma-ray assisted irradiation treatment are performed in sequence; wherein the parameters of the microwave pulse irradiation are: microwave power of 60 to 100 W, pulse width of 30 to 500 ns, pulse repetition frequency of 10 to 800 Hz, and treatment time of 20 to 50 min; during the gamma-ray assisted irradiation process, the absorbed dose rate of the mixture is 10 to 30 Gy / min, and the absorbed dose is 400 to 1600 Gy.

8. The method for preparing a covalent organic framework material capable of adsorbing sulfonamide antibiotics according to claim 6, characterized in that: The microwave pulse irradiation and gamma-ray assisted irradiation treatment adopt an alternating irradiation method: during the microwave pulse irradiation treatment, after preheating for 3 to 10 minutes, the mixture is stopped for 2 to 5 minutes, and the gamma-ray assisted irradiation treatment is performed when the microwave pulse irradiation treatment is stopped. When the microwave pulse irradiation treatment is completed, the absorbed dose rate of the mixture is increased by 50 to 80 Gy / min until the absorbed dose of the gamma-ray assisted irradiation treatment is met.

9. Application of a covalent organic framework material capable of adsorbing sulfonamide antibiotics, the covalent organic framework material prepared by the method for preparing a covalent organic framework material capable of adsorbing sulfonamide antibiotics according to any one of claims 1 to 8, characterized in that: It is applied in the adsorption of sulfonamide antibiotics in water; The application method is: adding the covalent organic framework material to a polluted water body containing sulfonamide antibiotics, and oscillating and adsorbing for 1.5 to 2.5 hours at 28 to 32° C. and 175 to 185 rpm, wherein the mass ratio between the amount of the covalent organic framework material added and the content of the sulfonamide antibiotics in the water body is 10 mg:1 μg.

10. The use of a covalent organic framework material capable of adsorbing sulfonamide antibiotics as claimed in claim 9, characterized in that: After the oscillation adsorption, the covalent organic framework material adsorbed with sulfonamide antibiotics is immersed in 0.1 mol / L hydrochloric acid and washed with ultrasonic oscillation for 3 to 7 times at room temperature, with each treatment lasting 1.8 to 2.2 hours, so as to desorb the sulfonamide antibiotics and realize the recycling of the covalent organic framework material.

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